Beginner java code script not loading images

[cov010]

I have been trying for the last 2 days to get what seems like a simple to script to run. I have the following var setup

<script type="text/javascript">

var rNumber = randInt(5);// generate a random integer from 1 to 5
var rAd = adDescription(rNumber);// description of the random ad
var rLink = adLink(rNumber);// URL of the random ad

Now I need I need to enter a command to write the text

< a href="url">
<img src="adn.jpg" alt="description" />
</a>

Where the url is the value of the rLink variable

n is the value of the rNumber variable

description is the value of the rAd variable

This is what I added


<script type="text/javascript">

var rNumber = randInt(5);// generate a random integer from 1 to 5
var rAd = adDescription(rNumber);// description of the random ad
var rLink = adLink(rNumber);// URL of the random ad

document.write("<a href='adLink'>");
document.write("rNumber");
document.write("<img src='"ad + randInt + .jpg"' alt='adDescription' />");
document.write("</a>");
</script>

Problem is nothing shows when I open the page what am I doing wrong?